JPS5935967A - Printing mechanism for small printer - Google Patents

Abstract

PURPOSE:To achieve a clear printing preventing direct contact of the ink ribbon with a printing paper by providing an opening or a ribbon mask between the paper on a platen and the ink ribbon. CONSTITUTION:When a plunger 14 is energized, a iron core 14a moves a guide shaft 9 in the direction of the arrow A against a spring 12 to push up a carriage 9 and a print head 1, producing a large clearance between a platen 2 and the printing head 1, which facilitates the insertion and feeding of a printing paper 5 and the winding of the ink ribbon 4. Then, when the energization of the plunger 14 is cut off to print, the guide shaft 9 moves in the direction of the arrow B with the spring 12 to press an ink ribbon 4, a ribbon mask 7 and the printing paper 5 toward the platen 2. This reduces the clearance between the print head 1 and the platen 2 to get the printing paper 5 tight on the platen 2 smoothing the warping and folding thereof 5 while preventing direct contact of the ink ribbon 4 with the paper 5 with an aid of the ribbon mask 7 provided before the paper 5, eliminating staining in printing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing mechanism for a small printer. For more information,
This invention relates to an improvement in the printing mechanism of a small printer that prints on a thick recording medium consisting of multiple sheets of printing paper using a print head.

The printing mechanism conventionally used in impact-type dot printers that print by wire has a certain gap t'2 between the print head 101 and the platen 102, as shown in the cross-sectional view of the printing section in FIG. and print paper 10 in the gap t.
5 was inserted, and printing was performed by striking the printing paper 105 with a wire through the ink ribbon 104. However, as shown in the figure, for example, the mount (
Cover) 105α and multiple sheets of paper 105b.
- When a recording medium such as 105b is inserted under the print head 1 (01), the gap tK widens due to the reaction force between the backing paper and the paper, the fold p, and the thickness of the pages of the paper 105b to be printed. If the print head 101 prints while moving in this state, the ink ribbon 104 will come into direct contact with the surface of the paper 105b, resulting in ink stains, and the paper will move, causing the printing position to shift. There was a drawback that it was difficult to use.

Furthermore, if there is a gap between the mount 105α and each paper 105b, the printing energy of the print head wire will be absorbed by the floating paper and will not be sufficiently transmitted to the printing surface, resulting in clear printing. It had the disadvantage that it could not be done. Similar drawbacks occur not only when printing on passbooks, but also when printing on multiple sheets of carbon paper or copy paper made of pressure-sensitive paper. Furthermore, when paper is fed multiple times to start a new line, the paper is not completely fed due to the large load, and the ink ribbon winding load is also increased.

The purpose of the present invention is to eliminate such drawbacks, and the purpose of the present invention is to provide clear, stain-free printing on thick recording media such as passbooks and copy paper, and to provide a method for paper feeding and ribbon winding. An object of the present invention is to provide a highly reliable printing mechanism for a compact printer with a completely reduced load.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a front view of the printing mechanism of a small printer showing an embodiment of the present invention, FIG. 2 is a side view showing the print head in a state where the suppression is released, and FIG. 3 is a side view showing the printing mechanism. Shows the state of being pressed by the head.

8.9 is a first guide shaft 8 and a second guide shaft 9 that slidably guide the carriage io on which the print head 1 is mounted;
The first guide shaft 8 is fixed to the printer frame 13, and the second guide shaft 9 is held by the printer frame 13 so as to be movable in the front and rear directions with respect to the platen 2. A spring member 12 is applied to both ends of the second guide shaft 90 to bias the second guide shaft 9 in the direction of arrow B. The gear ridge lO on which the print head l is mounted has a hole into which the second guide shaft 9 is inserted, and a long four-hole fil a which slidably engages with the first guide shaft 8. Since the second guide shaft 9 is biased in the direction of arrow B, the print head 1 fixed to the carriage IO is also biased in the direction of arrow B (the print direction). The plunger 14 is fixed to the printer frame 1:3. When the plunger 14 is energized, the iron core 14α pushes up the second guide shaft 9 in the direction of the arrow A, and the carriage 1 (1'l) Directional suppression is lifted.

A platen 2 is fixed to the printer frame 13, and a ribbon cassette 6 and a paper feeding pinch lawn 1 are provided.

Next, details of the ribbon cassette 6 used in one embodiment of the present invention will be explained with reference to a perspective view of the ribbon cassette in FIG. The difference from the general structure is that, as shown in the figure, a thin film-like ribbon mask 7 is provided on the front side of the ink ribbon 40, and portions 7a at both ends are attached to the inner arm portion 6α of the ribbon cassette. A rectangular opening 7b is provided in the center of the ribbon mask 7, through which the print head 1 moves to perform printing.

Next, the operation will be explained. When the plunger 14 is energized, the iron core 14α moves the second guide shaft in the direction of the arrow against the spring member 12. Therefore, the carriage 9 and the print head 1 are also pushed up, creating a large gap tl between the platen and the print head 10, as shown in FIG. In this state in which the printing head is not suppressed, the printing paper 5 can be inserted easily, and the paper feed for line feed and the ink ribbon winding are pressed by the print head 1. Since there is no load, there is no load and the operation is completely performed.

When printing next time, when the plunger 14 is de-energized, the second guide shaft 9 moves in the direction of the arrow B under the tension of the spring part #12, so the print head l on the carriage also moves in the direction of the arrow B. Ink ribbon 4, ribbon mask 7, and printing paper 5'
f. Press the Danten in two directions. The wrinkles and folds of the printing paper are stretched out to form a narrow gap of 1°.

In this state, there is a narrow gap t2 between the print head 1 and the platen 20, and the slightly folded edges of the printing paper are extended and brought into close contact with the platen 2. In this state, print head 1
When printing while moving, the ribbon mask 7 is provided in front of the printing paper 50, so the ink ribbon 4 and the printing paper 5 do not come into direct contact, eliminating the occurrence of printing stains and preventing the printing paper from lifting. The printing energy of the wire is effectively transmitted to the printing surface, resulting in clear printing.

Note that when printing is performed, ribbon feeding and paper feeding are stopped, and printing is performed while the ink ribbon 4 and printing paper 5 do not move relative to each other.

Although the description has been made by using a plunger to move the means for releasing the suppression of the print head, it is also possible to use a cam mechanism as the releasing means. Furthermore, it is also possible to press with a plunger or the like and release the suppression with a spring member, and the range of deicing is not limited.

As described above, when inserting printing paper, feeding the printing paper, and winding up the ink ribbon, N' is widened between the print head and the platen, and the ink ribbon is widened when printing. The printing mechanism of a small printer, which prints by placing a ribbon mask in front of it and printing while pressing the paper with the print head and platen, is suitable for copy printing using bank passbooks, multiple sheets of carbon paper, or pressure-sensitive paper. In this method, there is no movement of the printing paper, there is no dirt, high quality and clear printing can be performed, and highly reliable paper feeding and ribbon winding can be achieved.

Furthermore, in order to release the print head from being suppressed, the guide shaft of the carriage is moved using a plunger or cam mechanism, which simplifies the structure and makes it possible to easily control the timing of electrical and mechanical operations. It is effective as

[Brief explanation of the drawing]

FIG. 1 is a front view of the printing mechanism of a small printer according to an embodiment of the present invention, FIG. 2 is a side view of the printing mechanism with the printing head released from suppression, and FIG. 3 is a side view of the printing mechanism. FIG. 4 is a perspective view of a ribbon cassette used in the present invention, and FIG. 5 is a sectional view of a conventional printing section. 1 is a print head 2 is a platen 4 is an ink cartridge 8-bon 5 is a printing paper 6 is a ribbon cassette 7 is a ribbon mask 8 is a first guide shaft 9 is a second guide sleeve 10 is a carriage 11 is a pinch row 512 is a spring member 13 is a printer Frame Ahab〉Nsha. Above 9- Figure 2 Figure 3

Claims (1)

[Claims] A platen fixed to a printer frame, a print head that prints on a recording medium on the platen, an ink ribbon placed in front of the print head, and between the recording medium and the ink ribbon. a ribbon mask provided on the printer frame, a first guide shaft fixed to the printer frame, a second guide shaft held on the printer frame so as to be movable in the platen direction, and a guide shaft for inserting the second guide shaft. a carriage having a hole and an elongated size that slidably engages with the first guide shaft, the carriage having the print head mounted thereon, guided by the first guide shaft and the second guide shaft, and reciprocating across the recording medium; and a biasing means for biasing the second guide shaft toward the platen, and a releasing means for releasing the bias from the biasing means, and during printing, the biasing means causes the print head to move toward the platen. Ink ribbon, 1- The ribbon mask is configured to press the recording medium against the plan, and release the suppression of the print head by the release means when feeding the recording medium and feeding the ink ribbon. The printer's printing mechanism.